Abstract
Hyperekplexia (startle disease) is an unusual, familial, neurological disorder characterized by abnormally enhanced startle response, followed in most cases by momentary generalized muscular stiffness. These attacks may cause the patients to fall rigidly, while remaining fully conscious. Startle symptomatology has generally an onset in infancy and is often accompanied, during the first years of life, by rigidity, sleep myoclonus, motor delay, regurgitation and apneic spells, which may cause sudden death. Stiff-baby syndrome is a familial disorder characterized by marked rigidity, with neonatal onset and gradual reduction during infancy, regurgitations, motor delay and attacks of stiffness. We report 4 new cases of hyperekplexia from two different families and another infant with stiff-baby syndrome discussing clinical, electrophysiological and genetic aspects of both neurological disorders in relation to other reported cases. We suggest a continuum between these familial syndromes, which are often misinterpreted as epilepsy or other disorders.
Sommario
L'iperekplexia (o malattia degli startles) è una rara malattia neurologica, su base ereditaria, caratterizzata da una abnorme risposta startle, seguita nella maggior parte dei casi da un temporaneo irrigidimento muscolare generalizzato. Questi attacchi possono far si che il paziente cada rigidamente senza perdita di coscienza. Le risposte startle abnormi in genere iniziano nel corso dei primi anni di vita e sono accompagnate, in tale periodo, da rigidità, mioclonie del sonno, ritardo motorio, rigurgiti e da attacchi di apnea che possono provocare una morte improvvisa. La stiff-baby syndrome è una malattia ereditaria caratterizzata da accentuata rigidità ad esordio neonatale che regredisce gradualmente nel corso dei primi anni di vita. Si osservano inoltre rigurgiti, ritardo motorio e attacchi di irrigidimento muscolare.
Vengono descritti quattro nuovi casi di iperexplexia provenienti da due diverse famiglie e un altro bambino con stiff-baby syndrome. Vengono discussi gli aspetti clinici, genetici ed elettrofisiologici di entrambe le patologie, confrontandoli con gli altri casi descritti in letteratura. Si suggerisce la presenza di un continuum tra queste due sindromi ereditarie, spesso confuse con forme epilettiche o con altre patologie.
Similar content being viewed by others
References
Andermann F., Andermann E.:Startle disorders of man: hyperekplexia. Jumping and Startle Epilepsy. Brain & Devel. 10:214–222, 1988.
Andermann F., Keene D.L., Andermann E., Quesney L.F.:Startle disease or hyperekplexia: further delineation of the syndrome. Brain 103:985–997, 1980.
Dalla Bernardina B., Fontana E., Colamaria V. et al.:Neonatal hyperekplexia. In: Beaumanoir A., Gastaut H., Naquet R., eds. Reflex Seizures and Reflex Epilepsies. Geneva: Editions Medicine et Hygiene. pp. 461–474, 1989.
de Groen J.H.M., Kamphuisen H.A.C.:Periodic nocturnal myoclonus in a patient with hyperekplexia (startle disease). J. Neurol. Sci. 38:207–213, 1978.
Dooley J.M., Andermann F.:Startle disease or hyperekplexia: adolescent onset and response to valproate. Pediatr. Neurol. 5:126–127, 1989.
Gastaut H., Villeneuve A.:The startle disease or hyperekplexia: pathological surprise reaction. J. Nerv. Ment. Dis. 5:523–542, 1967.
Hallett M., Chadwick D., Marsden C.D.:Cortical reflex myoclonus. Neurology 29:1107–1125, 1979.
Klein R., Haddow J.E., De Luca C.:Familial congenital disorder resembling stiff-man syndrome. Am. J. Dis. Child. 124:730–731, 1972.
Kurczynsky T.W.:Hyperekplexia. Arch. Neurol. 40:246–248, 1983.
Lingam S., Wilson J., Hart E. W.:Hereditary Stiff-baby syndrome. Am. J. Dis. Child. 135:909–911, 1981.
Markand O.N., Garg B.P., Weaver D.D.:Familial startle disease (hyperekplexia): electrophysiologic study. Arch. Neurol. 41:71–74, 1984.
Morley D.J., Weaver D.D., Garg B.P., Markand O.:Hyperekplexia: an inherited disorder of the startle response. Clin. Genet. 21:388–396, 1982.
Saenz-Lope E., Herranz-Tannarro F.J., Masdeu J.C., Chacon Pena J.R.:Hyperekplexia: a syndrome of pathological startle responses. Ann. Neurol. 15:36–41, 1984.
Suhren O., Bruyn G.W., Tuynman J.A.:Hyperekplexia: a hereditary startle syndrome. J. Neurol. Sci. 3:577–605, 1966.
Tohier C., Roze J.C., David A. et al.:Hyperekplexia or stiff baby syndrome. Am. J. Dis. Child. 66:460–461, 1991.
Touwen B.C.L.:Neurological Development in Infancy CDM No. 58. London: Heinemann, 1975.
Vigevano F., Di Capua M., Dalla Bernardina B.:Startle disease: an avoidable cause of sudden infant death. Lancet I:216, 1989.
Weaver D.D., Morley D.J., Garg B.P., Markand O.:Hyperkplexia: not hereditary stiff-baby syndrome. Am. J. Dis. Child. 136:562, 1982.
Wilkins D.E., Hallett M., Wess M.M.:Audiogenic startle reflex and startle syndromes. Brain 109:561–573, 1986.
Author information
Authors and Affiliations
Additional information
This study was supported in part by grants of the Italian Ministry of Health. (Current Research Projects 1989)
Rights and permissions
About this article
Cite this article
Cioni, G., Biagioni, E., Bottai, P. et al. Hyperekplexia and stiff-baby syndrome: An identical neurological disorder?. Ital J Neuro Sci 14, 145–152 (1993). https://doi.org/10.1007/BF02335749
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02335749